One of the operational challenges for combat forces is in counter-sniper operations. Optical augmentation (OA) techniques can be used for sniper detection and interception. In this invention, detection of retro-reflection from a target optics of a transmitted light source is used as the detection approach. Implementation of this retro-reflection approach is by transmitting a light source and observing its reflection from a distant optics co-axially with respect to the illuminating source. Co-axial reflection is from retro-reflection. Other, specular and diffuse type reflections from a targeting optics as well as other reflecting objects would give rise to clutter in the sensor, causing false alarm detections. Clutter error is corrected by using a second sensor that is laterally shifted relative to the axis of illumination of the source. This sensor would collect all reflections such as specular and diffuse reflections that would other wise give rise to clutter. Since the co-axial sensor would receive the desired retro-reflection (though, plus clutter of specular and diffuse reflections), a differential signal of the co-axial and off-axial sensors would tend to yield a true retro-reflection component signal. This differential measurement is expected to vastly reduce false alarms for retro-detection. In addition to detecting the targeting optics, there is capability of discriminating and classifying various different types of optics used by a sniper, e.g., since the reflecting properties of the optics would have a spectral dependence, different wavelengths of illumination would be expected to produce different intensities of the retro-reflections. Select targets for detection in this invention would be of a sniper and especially his/her weapon. Retro-reflection of various wavelength (colors) may be from a human eyeball (particularly the retina), gun scopes (particularly the reticle on a gun sight telescope), and cameras, e.g., and these have known, target wavelengths. Ordinarily in the noise detected as opposed to retro-reflection detected categories would be stray metals, glass, headlamps of a car, which ordinarily provide only diffuse reflections or mirrors which ordinarily provide only specular type reflections. The illumination sources in this invention can be used either simultaneously or alternatively dictated by the frame rate of the system. Both these sources will provide co-axial illumination of the threat target area. The retro-reflections from the target will be at the spectral wavelengths of the two illumination sources. Each of these sensors will have adequate sensitivity to detect the retro-reflected light at the corresponding wavelength of the illumination source. Thus, a target optics can be detected.